I'll follow this thread because it's also something I really miss in the game. Since BF3 (at least regarding a game from the Battlefield series) I was playing HC only. I can't remember that I ever played a normal game in BF3 and BF4. Which also meant: after buying BF V (along with expecting an existing HC-mode) it was a hard time for me to be able to play.
If you are used to hit your opponent with one single bullet when using a sniper rifle (or two if you use a semi sniper rifle), it's worse if you have to hit the same three or more time to get him down. Also, I always love to play close quarter combat. In BF V, the amount of explosives flying around is disgusting. Friendly fire can lead to a much more interesting experience than that stupid grenade/noob tube spam we have now in the game. Also, in former times we used to play this game some kind of tactical/realistic. Not possible here. Marking an enemy (or better: getting marked by an enemy) is more of less the spears head regarding realism.
I know that there will not come any usable HC-mode in BF V, but I also know that I will only buy the next BF if there is such a mode. I still don't really like this arcade gaming like it's now.